low excretors either heterozygous or homozygous for the dominantallele. Striking differences in the incidence of high excretors in various populations have been demonstrated, and it appears thatthis genetic polymorphism may be of considerable valug in anthropo-genetic investigations.*':?? As part of the study of the genetic relationships And origins of various Pacific peoples, this report extends observations on BAIB excretion to the Micronesians inhabiting the Marshall Islands. The fact that some of the Micronesians were exposed to considerable radiation in 1954 is of special interest here, since it is known that radiation exposure can, temporarily at least, increase BAIB excretion,”* and studies on the Marshallese population may elucidate possible long-term effects. Urine samples from 65 exposed and 119 unexposed people (75.7% of the populationofthe village) were collected in plastic bottles containing thymol preservative. The sexes were equally represented, and the ages varied from 3 to >70 years. In somecases several members of the same family were included, and some kinships suitable for genetic analysis were available. Eighteen samples collected on Utirik were also studied. Urines were kept at 4°C and shippedin refrigerated containers to Seattle for analysis. These studies were carried out by one of us (B.S. Blumberg) and Dr. S.A. Gartler of the Department of Medicine, School of Medicine, University of Washington. Studies were completed 2 to 3 weeks after collection of the specimens. Determinations of BAIB werecarried out by high voltage electrophoresis on paper,?‘ and creatinine was determined bythe alkaline picrate method. Radionuclide Body Burden Evaluation The methods used in the radionuclide body burden evaluation are described later in a sepa- rate section. 1960 Survey BACKGROUND MATERIAL The 1960 survey was reducedin size and scope and limited to a very brief examination of the exposed people only. Several factors brought about this change. The people had recoveredto the extent that certain special examinations previously carried out every year need be doneonly once every two to three years. In addition, as pointed out before, the Trust Territory officials were concerned aboutthe slowness of economic recovery of the Rongelapese andfelt that the numerous visiting scientific teams, particularly those with igrge ships and crews, were partly responsible for the unrest of the people and therefore requested that the size of the surveys be kept'to a minimum,it was decided to defer the gammaspectrogegphic analysis until 1961. The Trust Territory officials agreed to greater participation of their medical personnelin future surveys andto the use of one of their cargo ships (Figure 9), which routinely madethe rounds ofthe islands for gathering copra, for carrying out the survey at Rongelap. Accordingly, for the 1960 survey the team consisted of only one physician and onetechnician from Brookhaven National Laboratory, and the re- mainderof the medical group, arranged by the Trust Territory, included its Director of Public Health, two Marshallese medical officers, and two Micronesian laboratory technicians. The Director of Dental Services and oneofhis dental officers also accompanied the team to carry out treatment of the people. The District Administrator of the Marshall Islands accompanied the team in order to consult with the people on their agricultural program.* As in the previous year, several of the exposed people now living at Kwajalein and Majurc «tolls were examinedatthese atolls prior to the Rongelap visit. PROCEDURES As in previous surveys, examinations were carried out in the dispensary and the schoolhouse in Rongelapvillage. Interval medical histories and complete physical examinations were carried out *Again in 1960, when the team arrived at Rongelap, the magistrate requested a meeting with the people. The line of questions and discussion was about the sameas that reported for the previous year. Resistance toward the examinations was expremed by only one or two of the people. Objections were again raised against the ban on eating coconut crabs, which selectively concenerate Sr** to such an extent that their consumption had to be prohibited (Figure 4). The people were assured that these crabs were being repeatedly examined and that, when it was safe to eat them, immediate notification would be given. Fish poisoning apparently had been less of a problem duringthe past year since only one case had been noted, and the subject was not brought up again. Following this meeting, cooperation by the people in the examinations was almost complete. ‘ ioe 14